Sherwood — Impeller Kit — S10077K

The Sherwood 10077K Impeller Kit is a complete raw water pump service kit for compatible Sherwood marine pump assemblies used on generators, small inboard engines, and marine cooling systems. The kit includes a precision-molded neoprene impeller with a brass keyed hub, plus the required gasket and O-ring components needed for routine pump service.

This impeller helps maintain proper raw water flow through the engine or generator cooling circuit, protecting the heat exchanger, exhaust system, and engine components from overheating.

Key Features

• Genuine-style Sherwood raw water pump impeller service kit.
• Part number: 10077K.
• Alternate format: S10077K.
• 12-blade flexible neoprene impeller.
• Brass hub with 1/2 in. keyed shaft design.
• 3/32 in. keyway reference.
• Includes impeller, O-ring, and gasket components where supplied.
• Designed for freshwater and saltwater raw water pump service.
• Commonly used on Onan marine generators, Westerbeke engines, Universal engines, and classic inboard applications where specified.
• Helps restore cooling water flow and reduce overheating risk.

Impeller Specifications

• Impeller type: flexible raw water pump impeller
• Material: marine-grade neoprene
• Blade count: 12
• Outer diameter: 2-1/4 in. / 57 mm
• Width: 25/32 in. / approximately 20 mm
• Shaft size: 1/2 in. / 12.7 mm keyed
• Keyway: 3/32 in.
• Hub type: brass keyed hub
• Service: marine raw water cooling pumps

What’s Included

Kit contents may vary slightly by packaging version, but typically include:

• Sherwood flexible impeller.
• O-ring.
• Cover gasket or gaskets.
• Required sealing components for standard impeller service.

Engine & Generator Compatibility

Common application context includes compatible Sherwood pump systems used on:

• Onan marine generator applications.
• Westerbeke diesel engines.
• Universal marine diesel engines.
• Chris-Craft 283 and 430 applications where listed.
• Gray Marine engine applications where listed.
• Small inboard marine engine cooling systems using compatible Sherwood pump assemblies.

Onan application context commonly includes generator families such as:

• MDKAA
• MDKAB
• MDKAL
• MDKAV
• MDKAW
• MDKAZ
• MDKBG / MDKBK / MDKBL / MDKBM / MDKBN
• MDKDK / MDKDL / MDKDM / MDKDN

Use this kit only where the generator model, engine serial number, pump model, shaft size, and impeller dimensions confirm compatibility.

Sherwood Pump Compatibility

Common Sherwood pump fitment references include:

• R30G
• G701 / G701-01
• G702 / G702-01
• H70 / H80
• E05 / E20
• A03 / A20

Confirm the pump model before ordering, especially on older engines or generators where the raw water pump may have been replaced or rebuilt with different components.

Serial Number Fitment Notice

Fitment depends on the exact raw water pump model, engine or generator serial number, shaft diameter, keyway, impeller width, and cover gasket style. This kit requires a compatible 1/2 in. keyed shaft pump.

Flexible impellers can look similar but may differ in diameter, depth, hub style, shaft size, blade count, and gasket requirements. Match the impeller being removed whenever possible.

When This Part Needs Replacement

Replace the impeller during scheduled cooling system service, after overheating, after dry running, after long storage, or whenever raw water flow becomes weak or inconsistent.

Replacement is also recommended if the impeller blades are cracked, stiff, missing, permanently bent, swollen, or damaged. A failed impeller can cause overheating and may send broken rubber vanes downstream into the heat exchanger, oil cooler, or exhaust system.

Recommended service interval is typically annually or every 100 hours, depending on engine use, water conditions, and manufacturer maintenance guidance.

Installation Notes

Lubricate the new impeller before installation using glycerin, soapy water, or an approved impeller lubricant. Do not install the impeller dry. Make sure the key is properly seated in the shaft and the impeller hub before sliding the impeller into the pump body.

Twist the blades in the correct direction during installation, replace all supplied gaskets and seals, and inspect the pump cover, wear plate, cam, shaft, and housing for scoring or corrosion. After startup, confirm strong raw water discharge and check the pump cover for leaks.

Alternate / Cross-Reference Part Numbers

• Sherwood 10077K — primary kit part number
• Sherwood S10077K — alternate catalog format
• Sherwood 22783 — related Sherwood reference; verify by pump model
• Onan 132-0375 — cross-reference reference; verify by generator model and spec
• Onan 132-0379 — cross-reference reference; verify by generator model and spec
• Onan 132-0498 — cross-reference reference; verify by generator model and spec
• Onan 541-1519 — cross-reference reference; verify by generator model and spec
• Westerbeke 11764 — cross-reference reference; verify by engine model
• Westerbeke 33100 — cross-reference reference; verify by engine model
• Westerbeke 33112 — cross-reference reference; verify by engine model
• Universal 200208 — cross-reference reference; verify by engine model
• Universal 200496 — cross-reference reference; verify by engine model
• Universal 287439 — cross-reference reference; verify by engine model
• Crusader 727103 — cross-reference reference; verify by application
• Chris-Craft 16.80-90047 — cross-reference reference; verify by application
• Sierra 23-3310 / 23-2000 / 23-3302 — aftermarket references; verify by pump model
• JMP 7110 / 7110-01K — aftermarket references; verify by pump model
• CEF 500166 — aftermarket reference; verify by pump model
• Mallory 9-45716 — aftermarket reference; verify by pump model

Parts Desk Insight

This is a common small-frame Sherwood impeller kit used across many generator and compact inboard pump setups. The most important fitment checks are the 2-1/4 in. diameter, 25/32 in. width, 1/2 in. keyed shaft, and 3/32 in. keyway. When replacing the impeller, inspect the pump cover and cam at the same time, since worn pump surfaces can reduce cooling flow even with a new impeller installed.

Shipping: Ships same or next day for fast Canada wide shipping. ⚓